U.S. Defense Secretary Leon Panetta ordered senior Pentagon officials on July 18 to begin monitoring major U.S. news media for disclosures of classified information in an effort to stop the release of government secrets after a series of high-profile leaks.

Reports about U.S. cyber warfare against Iran, procedures for targeting militants with drones and a double agent who penetrated a militant group in Yemen have angered U.S. lawmakers. Some have charged the leaks were timed to benefit President Barack Obama’s re-election bid. Representative Buck McKeon told a news conference later that he did not believe the Pentagon was behind the leaks and that Panetta and the other officials were taking the issue seriously. “Both the chairman and I were very convinced that Secretary Panetta and all of the folks at the Pentagon are taking it seriously, are trying to mitigate the damages and prevent it in the future,” said Adam Smith, the top Democrat on the panel.

In addition to the media monitoring ordered by Panetta, the Pentagon said it had taken a number of other steps in recent months to improve information security. The measures included improved training for handling classified information, the publication of a manual with clear instructions on what constitutes an unauthorized disclosure and the creation of an online security incident reporting system.